One of the biggest mysteries these days in the world of high-end Manhattan commercial real estate is the fate of the long troubled 666 Fifth Avenue, the 41-story embossed-aluminum office tower that the family of Jared Kushner bought for $1.8 billion at the height of last decade’s real-estate boom, and promptly booted. For months the question has been debated, often gleefully: will the Kushners be able to pay off the building’s massive $1.4 billion debt when it comes due in February? Or will the Kushners’ bondholders—the debt is in the form of commercial mortgage-backed securities— foreclose on the building, wiping out the Kushners’ equity and possibly that of their minority partner, Vornado Realty Trust, controlled by real-estate mogul Steve Roth?

Under normal circumstances, the financial drama transpiring at 666 Fifth Avenue might interest a handful of Wall Street types. But given that Jared is a senior White House adviser and that his father-in-law is the alpha beta-carotene president of the United States, what happens to Jared’s Fifth Avenue play toy has become riveting—especially because the family’s flamboyant purchase of the building, for a record price per square foot, was meant to signal that the Kushners had arrived in Manhattan, and were no longer to be thought of simply as the owners of two-bit New Jersey garden condominiums and shopping malls. In that strategy, of course, the Kushners were hoping to take a page from Donald Trump’s playbook from the 1970s, when his redevelopment of what is now the Grand Hyatt Hotel, on 42nd Street, signaled that the Donald intended to abandon his family’s real-estate roots in Queens and Brooklyn for the big stage.

The Kushners’ timing could not have been worse. They bought the building mostly with borrowed money and hoped to increase the rent that tenants paid. But after the Great Recession of 2008, that plan got scotched and some of the building’s bigger tenants fled. They sold off the retail space in 666 Fifth for $525 million to the Carlyle Group and Crown Acquisitions. In 2011, Vornado bought a 49.5 percent interest in the 666 Fifth office tower and also bought most of the retail space along Fifth Avenue from Carlyle and Crown for another $707 million. Vornado also agreed to invest up to $80 million in the building and to guarantee a portion of the mortgage, which was re-structured into a $1.1 billion note and a $115 million secondary loan. Interest on the mortgage of another $200 million has accrued, bringing the total owed by the Kushners to $1.4 billion.

The problem is that few real-estate experts think the building is worth the amount owed on the mortgage, let alone the $1.8 billion the Kushners paid for it. (Around 30 percent of the building remains vacant.) The Kushners have been on a worldwide spree to try to find a new equity investor that would enable them to possibly refinance the mortgage before it comes due early next year. They tried to get money from both Anbang, a large Chinese insurance company with close ties to the Chinese government, and from the former prime minister of Qatar, but both efforts foundered due to concerns, in part, that the Chinese and the Qataris might be trying to buy political influence with Trump and his extended family by making the deal. The Kushners also toyed with the idea of razing the building and commissioning Zaha Hadid Architects to build a sparkling skyscraper that one Twitter user likened to a Swarovski phallus, 40 stories taller than the current version, adding a hotel and presumably changing the building’s economics. (Hence the building's high vacancy rate.) But the Kushner’s Xanadu plan was nixed. Since then, the clock has been ticking.

On April 6, an apparent clue emerged as to how the Kushners planned to break the Gordian knot of 666 Fifth when Roth, in a public filing with the Securities and Exchange Commission, wrote that “we now have a handshake to sell our interest to our partner”—the Kushners—“at a price which will repay our investment plus a mezzanine-type return,” something in the range of 10 to 15 percent. Roth also wrote that the mortgage on 666 Fifth would be “repaid,” including the “portion of the debt that we hold.” He allowed that the outcome of the investment for Vornado was not the “outcome” that he “expected going in” to the 666 Fifth Avenue deal, but it was an “appropriate” outcome at the moment.

But the clue contained significant ambiguity. Despite being definitive that the deal would happen in the previous sentences, Roth concluded, “This situation continues to be fluid—there can be no assurance that a final agreement will be reached or that a transaction will close.”

Neither Roth nor the Kushners would comment for this article, but real-estate bankers I talk to deciphered the probable meaning of Roth’s cryptic filing. The purpose of the “handshake” announcement between the Kushners and Roth on 666 Fifth Avenue was to signal the market that there were terms on which Roth would agree to exit his partnership with the Kushners, assuming a new investor could be found. That fact allows the Kushners to circulate a term sheet to potential investors, who would then have at least a rough idea of what it would take to get Roth out. This is still a far cry from an actual deal—as Roth made clear in his S.E.C. filing—but it’s a hair better from the Kushners’ point of view, by at least giving them actionable terms they can use to find a new investor. The Kushners needed to know that Roth would sell “at a certain price,” one real-estate banker told me, “before they can go out and find replacement financing.” But, he continued, the bigger problem is “the property is underwater” and not likely worth the amount of the mortgage securities. He said he has not heard a peep in the market about the deal, and doubts any kind of refinancing is imminent.

This banker did, however, describe one way the Kushners could get a deal done for 666 Fifth while retaining a minority stake in the building. He said a new investor—perhaps Starwood or Apollo (which previously has made loans to the Kushners to refinance the mortgage on a Chicago skyscraper)—could invest a sufficient amount into 666 Fifth (he suggested around $350 million) to pay down enough of the existing first mortgage securities of $1.1 billion, allowing the banks or the securities market to refinance the new balance of $750 million, at an acceptable loan-to-value ratio of 60 percent, and push the amortization of the mortgage beyond next year. The new investor could also put in another $100 million or so to take out Vornado—its $80 million, plus a 10 percent or so return—and reduce the Kushners’ stake in the building down to a small minority position, giving them a chance to recover some of what they invested, assuming the building can be filled back up with tenants paying market rents. “That’s probably the way it’s going to work, and with Kushner as a partner, but also with Kushner having a subordinated equity interest with the right—if things really go well, to recover a portion of their equity investment or more,” he said. “But total upside play at that point.”

Jared and Ivanka attend a state dinner for the French President and his wife on April 24th.

By Aaron P. Bernstein/Getty Images.

In addition to trying to resolve their massive financial problem at 666 Fifth Avenue, the Kushners also appear to have started to position themselves for Javanka’s expected return to New York City from the White House probably “by the end of the year,” according to an experienced real-estate banker, who speculated that Kushner could return as C.E.O. soon thereafter. To that end, last week Charles Kushner, Jared’s ex-con of a father, gave a rare interview to CNN—off camera—in which he took the blame for the whole 666 Fifth debacle. “I pushed Jared to do the deal,” Charles said, adding that Jared had actually advised against doing it and that the deal was “bad timing and bad judgment.” This, of course, is more than just a little revisionist history and may have been designed to try to “cleanse” Jared, as this real-estate banker put it, of the taint of 666 Fifth when he again takes up the reins of Kushner Companies when he leaves Washington.

The Kushners also reportedly have another scheme up their sleeves. They have made a highly unusual $250 million offer to buy the 26-unit co-op apartment building at 417 Park Avenue—the only co-op on Park Avenue between 57th Street and Grand Central in an area replete with office towers—from its shareholders, the people who own apartments in the building. The Kushners’ offer would value each of the co-ops at around $9 million. Their idea, presumably, would be to then raze the building and erect a new office tower on the site, in keeping with the city’s new re-zoning of the neighborhood to allow much taller office buildings than currently exist. (A few blocks further south, JPMorgan Chase will be tearing down its 52-story headquarters and replacing it with a new 70-story office tower.) Normally, the sale of a co-op is hard to effect, since 100 percent of the owners have to approve the deal—my Wall Street sources say they have never heard of such a thing happening. But 417 Park, for some reason, reportedly only requires approval of two-thirds of the co-op owners; some 80 percent have already said they would support the Kushners’ offer. (The Macklowe family, another New York City real-estate titan, has also made an offer for 417 Park.) One influential real-estate magnate conceded that the move seemed rather clever.

Of course, what’s not the slightest bit clear is where the Kushners would get the $250 million they have offered to buy the building—let alone the billions more that would be needed to tear it down and build a new skyscraper. Another influential real-estate executive told me that the Kushners misjudged Jared’s ascent to the Trump White House, hoping it would help them recruit capital to their real-estate enterprise rather than deter organizations and countries fearful of the troubling optics. According to this person, the family business has turned into a “leprosy colony.”